Originally Posted by Pascoe

I haven't flow BA out of T3 in years - probably not since they opened T5 I reckon. Only EK, which was a trip with a nipper, in Y, with paid lounge access courtesy of my wife. So I'd actually be keen to do a longhaul sector out of there just to see it.

I guess BA have proactively sent these communications on the assumption that people just generally wouldn't prefer to fly out of T3 when there's a newer terminal with blingier shops and lounges over at T5. And for those with BA>>BA connections I guess it's more of a pain also. Hence maybe the choice of more touristy destinations rather than opting for eg ORD or similar. Just a guess.